US6406670B1 - Multiple well microtiter plate loading assembly and method - Google Patents

Abstract

An apparatus and method for simultaneously loading a plurality of small items such as small items into the wells of a multiple well microtiter plate which includes a small item loading unit and a small item insertion device. The small item loading device includes a top plate having a plurality of openings positioned to register with the microtiter plate wells and a closure unit to close the openings on one side of the top plate. The small item insertion device includes a base mounting a plurality of plunger pins which each register with a well in the microtiter plate. A movable deck unit is mounted in spaced relationship above the base and is provided with apertures, each of which receives a plunger pin. The small item loading device rests on the deck unit and the closure unit opens the openings therein to drop small items into the apertures over the pins. The deck unit is moved toward the base to cause the pins to enter the wells of a microtiter plate and seat the small items.

Description

BACKGROUND OF THE INVENTION

In the past, the insertion of small items into wells of various shapes formed in a plate has been a tedious and time consuming task. This has been particularly true when appropriately sized small items, such as porous polypropylene frits or other small items of composite material, were inserted into the multiple wells of a microtiter polypropylene plate such as a 1 mL 96 well microtiter plate. Such insertion has involved a manual technique wherein each item is individually placed into an empty well of the microtiter plate and is then manually seated in the well using a hand-held 5 mm rod.

SUMMARY OF THE INVENTION

It is a primary object of the present invention to provide a novel and improved multiple well microtiter plate loading assembly and method wherein a plurality of frits or similar small items are seated in wells in a receiving plate in a single operation.

Another object of the present invention is to provide a novel and improved multiple well microtiter plate loading assembly and method which includes a frit loading unit and a frit insertion device. The frit loading unit is designed to rapidly load a plurality of frits or other small items into apertures in the frit insertion device which includes a plurality of insertion pins to insert the frits simultaneously into the wells of a multiple well microtiter.

A further object of the present invention is to provide a novel and improved method for simultaneously loading a plurality of small items into the wells of a multiple well microtiter plate which includes providing a microtiter support unit with a plurality of frit receiving apertures extending therethrough which are arranged to correspond in position to the position of the wells in the microtiter plate. An elongate plunger pin is inserted into each of the apertures and a frit is loaded into each aperture to rest on the plunger pin. A microtiter plate is then inverted on the microtiter support unit with the wells aligned with the apertures, and the plunger pins are moved into the wells to seat the frits in the wells.

A still further object of the present invention is to provide a novel and improved apparatus for simultaneously loading a plurality of frits or similar small items into the wells of a multiple well microtiter plate which includes a frit insertion device including a base upon which a plurality of plunger pins are mounted so that each plunger pin registers with a well in the microtiter plate. A deck unit is movably mounted in spaced relationship to the base and includes a plurality of apertures extending therethrough, each of which receives a pin. A frit is placed on each pin within the apertures and the deck unit is movable toward the base to cause the pins to extend into the wells of a microtiter plate seated on the deck unit to seat a frit in each well.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of the frit loading unit for the multiple well microtiter plate loading device of the present invention;

FIG. 2 is a view in side elevation of the frit loading device of FIG. 1;

FIG. 3 is a plan view of a multiple well microtiter plate;

FIG. 4 is a perspective view of the microtiter plate of FIG. 3;

FIG. 5 is a perspective view of the frit insertion device for the multiple well microtiter plate loading device of the present invention; and

FIG. 6 is a plan view of the frit insertion device of FIG.5.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The multiple well microtiter small item loading assembly and method of the present invention will be described, for purposes of illustration, in connection with a microtiter well plate having 96 tubular wells for receiving small items of composite material or other small items such as circular polypropylene frits. It should be understood that other multiple well devices having more or less than 96 wells of various shapes other than circular can be loaded using the device and method of the invention. For purposes of this application, the small items to be loaded will be described as circular polypropylene frits, it being understood that other small items of various material and conforming shapes, such as composite material items, can be loaded in the manner to be described.

The multiple well microtiter plate loading assembly of the present invention includes two primary components; namely a frit loading unit and a frit insertion device. With reference to FIGS. 1 and 2, the frit loading unit indicated generally at10 includes aflat top plate12 having a plurality of spaced, frit receivingapertures14 extending through the top plate. These apertures are shaped and located to correspond to the shape and location of the open ends ofwells16 in a multiplewell microtiter plate18, such as the Beckman microtiter plate shown in FIGS. 3 and 4. Thewells16 have a substantial depth, as shown in FIG. 4, and it is important to fully insert each frit20 through the well opening22 and down towards thebottom surface24 of a receiving well such that the frits are not able to be dislodged.

Thefrit loading unit10 also includes a flatbottom slider plate26 which is no greater in width than thetop plate12 but is preferably longer than the top plate. Theflat bottom plate26 is formed to close theapertures14 when brought into flush engagement with a flat surface of the top plate. The top and bottom plates are relatively movable, but are temporarily held together, preferably by magnetic attraction. To accomplish this, one plate is provided with attached magnetic units while the remaining plate is provided with areas which are subject to magnetic attraction by the magnetic units. As shown in by FIG. 2, thetop plate12 can include a plurality ofmagnetic strips28 and30 to attract thebottom plate26 which is formed of steel or other metal subject to magnetic attraction. Obviously, the attracting magnets could be formed on the bottom plate to attract the top plate when the two plates are brought together.

Themagnetic strips28 and30 are of sufficient size and magnetic strength to affix the top and bottom plates together. To aid in overcoming this magnetic attraction and facilitate sliding the bottom plate away from the top plate to open theapertures14, the top and bottom plates are provided with cut-outportions32 and34 respectively which may be manually gripped to achieve relative sliding movement between the plates.

To use thefrit loading unit10, the flatbottom slider plate26 is engaged in flush alignment with thetop plate12 as shown in FIGS. 1 and 2 so that all of theapertures14 are closed by the bottom plate. Then a frit20 is loaded into each of theapertures14 either manually or by dipping the frit loading unit into a bin containing multiple frits. The depth of theapertures14 is such that a frit seated in each aperture has a top surface which is level with the top surface of thetop plate12. Multiple frits can be piled on the top plate and rapidly inserted in theapertures14 by spreading the frits across the top surface of the top plate. Once allapertures14 are filled, excess frits can be removed.

Referring to FIGS. 5 and 6, the frit insertion device indicated generally at36 includes abase plate38 having four spaced, upwardly projectingsupport pins40 secured with two at each end adjacent to the corners thereof. Each support pin is threaded at42 to receive anadjustment nut44. Spaced inwardly from thesupport pins40 and projecting upwardly from thebase plate38 are a plurality of spacedalignment pins46. Thebase plate38 is provided with a plurality of spaced, internally threaded holes which extend inwardly from the top surface of the base plate and are located to correspond to the location of thewells16 in the multiplewell microtiter plate18. Each of thespaced alignment pins46 is threaded at the bottom so that the pin can be threaded into an internally threaded hole in thebase plate38. Thus alignment pins can be removed from the base plate and replaced with alignment pins of a different length. The length and shape of each alignment pin is such that the pin will slide into awell16 and seat a frit20 at the bottom of the well when thefrit insertion device36 is used. Typically, for many microtiter plates, tapered alignment pins between two and three inches in length are sufficient.

Mounted on thesupport pins40 above thebase plate38 is adeck plate48 having openings at the corners of each end through which thesupport pins40 extend. The deck plate can move along the support pins toward and away from thebase plate38, but is normally maintained in spaced relationship above the base plate bysprings50 which surround the support pins. These springs engage the upper surface of the base plate and the lower surface of the deck plate to bias them apart. The normal position of the deck plate relative to the base plate can be adjusted by adjusting thenuts44 which engage the top surface of the deck plate.

Extending through thedeck plate48 are a plurality offrit receiving apertures52 which correspond in shape and location to thewells16 and thefrit receiving apertures14 in thetop plate12 of thefrit loading unit10. The deck plate is adjusted relative to thebase plate38 so that analignment pin46 projects into each of thefrit receiving apertures52 but terminates at a short distance from the top surface of the deck plate so that a frit20 can be received in eachfrit receiving aperture52 and rest on the end of an alignment pin.

Adjustably secured to the top surface of thedeck plate48 areelongate alignment guides54 and56 which may be moved toward and away from thefrit receiving apertures52. These elongate alignment guides are secured in place to thedeck plate48 by threadedbolts58 which extend through slots in the deck plate and the alignment guides and are held in place bynuts60. The bolts move in the slots in the deck plate to facilitate adjustment of thealignment guides54 and56.

In the operation of the multiple well microtiter frit loading assembly of the present invention, thefrit loading unit10 is first loaded withfrits20 in the manner previously described. Then the loaded frit loading assembly is placed onto the upper surface of thedeck plate48 with the flatbottom slider plate26 in engagement with the deck plate. The frit loading assembly is moved into engagement with theelongate alignment guides54 and56 which have previously been positioned to align thefrit receiving apertures52 with thefrit receiving apertures14 when the frit loading assembly engages the elongate alignment guides. Now, while theflat top plate12 is held in place, the flat bottom slider plate is slid outwardly away from thealignment guide54 to permit the frits from the frit receivingapertures14 to drop through into thefrit receiving apertures52. The frits now rest on the ends of thealignment pins46 which have been adjusted so that the frits project slightly upward from the top surface of thedeck plate48. Once the frits are loaded into the deck plate, thefrit loading unit10 is removed and the multiplewell microtiter plate18 is inverted and brought down over the deck plate with the open ends of thewells16 over thefrits20 infrit receiving apertures52. Since thefrits20 project slightly above the surface of the deck plate, they may be used to align themicrotiter plate18 so that each well16 is positioned to receive a frit. With themicrotiter plate18 inverted in place, it is then forced downwardly against thedeck plate48 to move the deck plate downwardly toward thebase plate38 compressing thesprings50. This causes the alignment pins to enter thewells16 inserting the frits on the ends of the alignment pins into the wells. When the frits are positioned in thewells16, the downward pressure on the microtiter is released causing thesprings50 to expand and return the deck plate to its original position. This results in withdrawal of the alignment pins from thewells16, and themicrotiter plate18 with the frits in place may now be removed from the deck plate. Before the microtiter is forced downwardly to lower the deck plate, a plate may be placed on the exposed surface of themicrotiter plate18 to prevent damage as it is forced downwardly against the bias of thesprings50.

Alternatively, it is sometimes possible to form thetop plate12 to correspond with the size of themicrotiter plate18 so that the microtiter plate can be inverted over the top plate without removing the top plate from thedeck plate48. The elongate alignment guides54 and56 would then be used to position the microtiter and the alignment pins46 would pass through thetop plate12 into thewells16.

Claims (10)

We claim:

1. An apparatus for simultaneously loading a plurality of small items into the wells of a multiple well microtiter plate, each of said wells having an open end to receive a small item, comprising:

a small item insertion device including a base;

a plurality of elongated plunger pins mounted on said base, each of said plunger pins including a pin base end secured to said base and a pin free end spaced above said base;

a deck plate mounted in spaced relationship above said base to receive said microtiter plate with the open ends of said wells adjacent to said deck plate, said deck plate including a plurality of apertures each for receiving the pin free end of one of said elongated plunger pins and a small item resting on the free end of said plunger pin, and

a deck plate mount secured to said base plate and engaging said deck plate to mount said deck plate in spaced relation above said base plate with the free pin end of each of said elongated plunger pins received in an aperture in said deck plate, said deck plate mount operating to permit movement of said deck plate toward said base plate whereby small items loaded into said deck plate apertures are inserted by said elongated plunger pins into the wells of a microtiter plate resting on said deck plate.

2. The apparatus for loading small items as described inclaim 1 further comprising a small item loading unit for loading small items into said deck plate apertures which includes a top plate having a plurality of openings therethrough registrable with said deck plate apertures for receiving said small items, and a bottom plate slidably movable with respect to said top plate for releasing said small items from said openings in said top plate when said top and bottom plates are positioned over said deck plate with said top plate openings in registration with said deck plate apertures.

3. The apparatus for loading as described inclaim 1, wherein said deck plate is mounted for reciprocal movement with respect to said base plate.

4. The apparatus for loading as described inclaim 3, wherein said deck plate mount includes at least one resilient element for biasing said deck plate away from said base plate.

5. The apparatus for loading as described inclaim 2, wherein said bottom plate is secured to said top plate for sliding movement relate thereto.

6. The apparatus for loading as described inclaim 2, wherein said deck plate includes an adjustable alignment mechanism for aligning the apertures of said deck plate with the openings of said top plate when said top and bottom plates are positioned on said deck plate.

7. The apparatus for loading as described inclaim 6, wherein said alignment mechanism includes a pair of adjustable guide bars for engaging different sides of said small item loading unit.

8. The apparatus for loading as described inclaim 1, wherein each of said plunger pins includes a threaded end engageable with a threaded bore in said base plate for mounting and adjusting the height of said pin.

9. The apparatus for loading as described inclaim 1, wherein said deck plate mount includes a plurality of rods for movably mounting said deck plate over said base and a spring mounted on each of said rods.

10. The apparatus for loading as described inclaim 5, wherein a magnet is mounted on one of said top and bottom plates to hold said plates together but to permit said bottom plate to slide relative to said top plate.

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